1. Technical Field
The present disclosure relates to illumination devices and, more particularly, to an LED illumination device having a reflector capable of producing a circular or square light pattern.
2. Description of Related Art
LEDs, available since the early 1960's and because of their high light-emitting efficiency, have been increasingly used. According to Illuminating Engineering Society of North America (IESNA), illumination distribution of lighting used in some occasions, such as squares, sidewalks, yards, parks, or parking lots must meet the standards of Type IV or Type V. These two types of standard require that the light illuminating on the site has a circular or square pattern, in which the light source is located at a center of the pattern. However, the light directly emitted from the LEDs usually cannot meet such a requirement. To meet the requirement, a lens which can modulate the light distribution of the LEDs may be used. However, the lens is expensive and when light travels through the lens the intensity of the light is significantly reduced. A reflector is cheaper than a lens and the light intensity will not be significantly reduced when the light is reflected by a reflector.
What is needed, therefore, is an illumination device having a reflector which can modulate the light generated by the illumination device so that the light pattern can meet the standards of IESNA Type VI and Type V.